Abstract
The measurements of hypersonic wave propagation velocity in the frequency range 2-7 GHz and ultrasonic wave absorption coefficient in the frequency range 10-60 MHz in thiophene have revealed the existence of two relaxation regions associated with vibrational specific heat: the first one associated with the first mode (v_1) of molecule vibrations and the second, associated with the remaining modes excluding the first one. It follows from the experimental values of hypersonic wave absorption coefficient that the bulk viscosity coefficient in this frequency range n_{y,∞} exceeds by a factor 2.5 the laminar viscosity coefficient n_s.References
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[2] — Ultraschallapparatur zur Messung von elaxationserscheinungen organischer Verbindungen, Acustica, 31, 14-21 (1974).
[3] L. A. DAWIDOWICZ, S. MACHKAMOW, Ł. PUŁATOWA, P. K. HABIBUŁŁAJEW and M. G. HALIULIN, Issledovanie akusticzeskich swojstw niekotorych orgamiczeskich żidkostiej naczastotach 0,3-3 GHz, Akusticzeskij Żurnał, 18, 318-320 (1972).
[4] K. F. HERZFELD and T. A. LITOWITZ, Absorption and dispersion of ultrasonic waves, Academic Press Inc., New York 1959.
